Carlo Ancelotti refused to blame the officials after Real Madrid's 3-2 loss at Rayo Vallecano, putting Monday's defeat down to a "bad game".
Oscar Trejo scored the winner for Roya with a retaken second-half penalty, converted after the VAR penalised Dani Carvajal for encroachment, to condemn Madrid to their first defeat in LaLiga this season.
Los Blancos trail Barcelona by two points at the top-flight summit after just their second loss to Rayo in 21 league games.
Madrid are also without a win in their last two LaLiga outings after a 1-1 draw with Girona and coach Ancelotti acknowledged his side struggled at Vallecas.
"We knew they played like that, they were more forceful than us in the duels. It was a bad game, that's it," the Italian said.
"It cost us. We had to change our strategy and we didn't. Then, in the duels, we lost a lot when we were not capable of being as forceful as our opponent.
"Vinicius [Junior] missed two or three shots that he normally scores. [Marco] Asensio has done well. It hasn't been a good game for us."
Madrid profited from a touchline review in the first half, with referee Juan Martinez Munuera deeming Asensio to have been felled by Fran Garcia inside the area before Luka Modric converted to equalise following Santiago Comesana's opener.
But Ancelotti's side were on the receiving end of overturned decisions in the second half after referee Munuera again consulted the screen to give a penalty for handball against Carvajal for Trejo's winner.
Despite the contentious decision for the winning goal, Ancelotti insisted he had no complaints towards Munuera as he acknowledged the role the VAR can play in the decisions.
Asked about the referee, Ancelotti said: "I have no opinion, none. VAR is involved in these things.
"We lacked freshness and it's normal after so many games... We have to make an evaluation of this first part of the season, we've done well.
"We're in the Champions League last 16 and we're doing well in LaLiga."
Madrid host Cadiz on Thursday in their final game before the November break for the World Cup in Qatar.